A disorder characterized by fluent linguistic function but poor performance on standard IQ tests and great difficulty with spatial processing. This syndrome is caused by the absence of about 28 genes from one of the two chromosomes numbered 7.

Williams syndrome

Fragile X syndrome is perhaps the most common genetic form of intellectual disability. It results when the trinucleotide repeats (i.e., CGG repeats) in the long arm of the X chromosome number more than 200 repeats, as opposed to the normal 6-50 repeats. This extension of repeats leaves this region of DNA fragile, or prone to breakage. Specifically, the overexpansion causes methylation and transcriptional repression of the Fragile X Mental Retardation 1 gene (*FMR1*), which encodes an important RNA-binding protein that inhibits RNA translation into proteins known as fragile X retardation protein (FMRP). The condition affects 1 in 3600 males and 1 in 8000 females. The reason for this large discrepancy between incidences in biological sexes is due to the fact that genetic females have two X chromosomes rather than one X like genetic males do. Generally speaking, females have one normally functioning *FMR1* on the non-mutated chromosome in each cell, which allows their symptoms to be milder since the amount of abnormal *FMR1* is more variable than in males.

Fragile X Syndrome

Rett Syndrome is a rare X-linked disorder usually caused by spontaneous (de novo) mutations in the methyl-CpG-binding protein 2 (*MeCP2*) gene. It affects almost exclusively genetic females (1 in 10,000 females). This is because genetic males only have one X chromosome and therefore don’t have dosage compensation occurring, lessening the amount of the mutated gene circulating. Genetic males with the syndrome either die in utero or in infancy due to the severity of the mutation phenotype. For 6 - 18 months persons with Rett Syndrome experience normal development, hitting the usual developmental milestones, until said development suddenly stops and regression begins. There’s usually a mild improvement in some social skills at around age 5, but regression (mental and physical) will continue for the rest of the person’s life.


Rett Syndrome

A disorder characterized by involuntary movements, especially involving the face, mouth, lips, and tongue. Can be caused by prolonged use of antipsychotic drugs, like chloropromazine

Tardive Dyskinesia

A rare form of epilepsy that manifests through loss of language. It develops when the child is between 3-7 years old. It is twice as common in males than in females. Individuals generally lose their ability to comprehend first and then lose the ability to speak. 

Some autistic traits seen with this syndrome include aggression, poor eye contact, insistence on sameness, and sleep problems. 

The cause of LKS is not known but many suggest it could be a dysfunctional immune system, virus exposure, or brain trauma. 

Landau - Kleffner Syndrome

Initial symptoms manifest in the first year of life and become more visible during early childhood. 

It derives from a missing portion of chromosome 15 from the maternal side. 


Angelman Syndrome

Core features of this disorder:
- impulsive eating, which can lead to being overweight
- compact body build
- undeveloped sexual characteristics
- poor muscle tone

Some Behaviors common with Autism:
- delays in motor development
- learning disabilities
- feeding problems 
- sleep disturbances
- skin picking
- temper tantrums

People who have this disorder are missing a portion of chromosome 15 but unlike Angelman Syndrome, receive this from the paternal side. 

Prader - Willi Syndrome

This list includes disorders or conditions that are related to autism or autistic states/features but are not currently directly or officially included in the DSM. These disorders include:

- Williams Syndrome
- Fragile X Syndrome
- Landau - Kleffner Syndrome
- Prader - Willi Syndrome
- Angelman Syndrome
- Rett Syndrome
- Tardive Dyskinesia


Santa Clara University

Autism Spectrum Disorder, commonly called just autism, is a neurodevelopmental disorder that impacts how people interact with others, as well as their ability to communicate, learn, and behave. While there are variations in the type and severity of symptoms presented among individuals with autism, they are classified as a singular spectrum disorder (Autism Spectrum Disorder) for diagnostic purposes.

Autism Spectrum Disorder(s)

No Author or Date. Related Disorders. Autism Research Institute. https://autism.org/related-disorders/#fragile-x-syndrome

Related Disorders 

The DSM-5-TR consolidates Autism and related symptoms into one singular disorder:
- Autism Spectrum Disorder


[DSM-5-TR] List of Autism Spectrum Disorder(s) Diagnoses

List of Other Recognized Autism Spectrum and Related Disorders

This list includes different types of methods for treating and/or managing different autism spectrum and related disorders. These include:
-	TBD



Treatment & Management Methods for Autism Spectrum and Related Disorders

This list includes different theories or concepts that are used to explain, define, or otherwise provide further insight into the workings of autism spectrum and related disorders. These include:
- TBD

Note: There is a separate subsequent node specifically for theories & concepts that are outdated and/or discredited. 

Theories & Concepts Relevant to Autism Spectrum and Related Disorders

This includes the intersection of connections and/or research related to autism spectrum and related disorders as a general category in other fields of study and research. Such fields include:
- Behavioral Neuroscience
- Biomedical Science
- Clinical Psychology
- Disability Studies
- Health Psychology
- Mindfulness

Note: Add subjects as needed


Interdisciplinary Connections & Research Related to Autism Spectrum and Related Disorders, General

The collection of references for node pertaining to Autism Spectrum and Related Disorders.

References for Autism Spectrum and Related Disorders

Autism stigmatization and peer communication references 

Rachel A Smith, a professor of communication Arts and sciences at the Pennsylvania State University, defines stigma as a set of beliefs regarding a specific social group that fosters a negative image amongst the general population. The stigmatization of Autism can be explored using Smith’s model of stigma communication (MSC). 

Autism Stigmatization

Early Intervention for ASD-Diagnosed Youth References

Early Intervention is a network of resources to assist infants and toddlers with developmental delays or disabilities up until the age of three. The objectives of Early Intervention are to facilitate development progress in social engagement and competence, cognitive skills, independence, and functional communication. 

Early Intervention for Autism

Autism Spectrum and Related Disorders

Biological motion is defined as movements made by living things. Some social interactions occur via biological motion. For example, reaching out one's hand for a handshake is a common form of biological motion.

Biological Motion

Non-biological motion is defined as movements made by non-living things, such as a ball bouncing on the ground or a car driving on the road.

Non-biological Motion

* Theory of double empathy
* Origins of term/theory
* Research
* Debate
* References

Double Empathy

The structural abnormalities in an autistic brain may have to do with the rate at which certain parts of the brain grow and develop. Anatomical findings show that the regions of the brain such as the frontal lobe and the amygdala develop prematurely in autistc children. When parts of the brain of the brain develop of of sequence, it can cause serious problems for the growth patterns of adjajcent regions.

Learn Before

Related

Learn After